Device and method for tracking time zone changes in communications devices

ABSTRACT

A portable processing device, such as a laptop computer, includes a time-of-day clock that is dynamically adjusted based upon occurrences of travel among different time zones. An itinerary is stored as a travel schedule of departure and arrival information and is used to identify anticipated multi-zone travel. When there is a coincidence between the clock and the occurrence of an anticipated multi-zone trip, the clock is automatically adjusted. The itinerary may be input via a user interface mechanism, such as a keyboard, may be entered by means of synchronization with a compatible program of a second device, or may be input via a network, such as the Internet. The determination of the relevant time zones preferably utilizes a database and most preferably utilizes an internal database of cities and time differentials among the cities. The dynamic adjustments of the time-of-day clock occur en route, without accessing externally generated signals or external devices.

TECHNICAL FIELD

The invention relates generally to portable devices having time-of-dayclocks and more particularly to techniques for updating time-of-dayclocks of portable devices based upon travel of the devices.

DESCRIPTION OF THE RELATED ART

There are a variety of types of portable processing devices thatmaintain a time-of-day clock to assist a user or to manage certainfunctions of the device. For example, a laptop computer, palmtopcomputer, or a personal digital assistant (PDA) is typically enabled todisplay the time of day. As users become more reliant on a portableprocessing device, such as a laptop computer, and upon calendaring andmessaging capabilities of the device, the precise time becomes moreimportant. This is particularly true of local area network (LAN)-basedtelephony clients. For example, telephony over LAN (ToL) systems may beconfigured to forward or inhibit forwarding of telephone calls basedupon the time of day. Whether the portable processing device isconnected to a hotel LAN port, a phone port or a wireless system,accurate behavior of the functions of the device is increasinglydependent upon tracking the time of day for accurate behavior.

One concern is that portable devices are often used by individualstraveling among cities that are in different time zones. As a personenters a different time zone, the person can use one of the userinterfaces of the device (e.g., a keyboard or computer mouse) to adjustthe time-of-day clock. In order to facilitate the process, some personalinformation manager (PIM) programs with electronic calendars and someoperating systems identify certain time zones and automatically computethe clock adjustment when a user selects one of the time zones. That is,the user selects a particular time zone in which the user and the devicehave been relocated, so that the device can automatically andimmediately alter the time zone setting and the time/date of theelectronic calendar. Even with the automated time zone adjustment,manual intervention by the user is required and is performed only at thetime of traveling. If the user enters a scheduled teleconference thattakes place in different time zones, the user must calculate the timedifference and the appropriate day and time for entry into theelectronic calendar. Since this process is sometimes difficult and proneto operator error, many travelers who carry laptops, PDAs, palmtopcomputers and similar devices often do not enter the time zone changes.

An improved system and method for scheduling and tracking events acrossmultiple time zones is described in U.S. Pat. No. 5,845,257 to Fu et al.A device includes an electronic PIM having a calendar/scheduling system.In operation, the system tracks different types of times, such as localtime, home time and remote time. “Home” time is determined by the timezone in which the user typically spends most of his or her time, such asthe location of the home office of the user. “Local” time is the timefor the locality in which the user is physically present at anyparticular instance. “Remote” time represents the time zones ofparticular other individuals. The system may show events andappointments in the user's own local time, regardless of the location inwhich the user is presently located. Identifying the three differenttimes, the system provides an improved means for managing activities,such as phone conferences across multiple time zones.

Using the Fu et al. system and method, upon arriving in a new time zone,the “local” time of the system is either automatically or manuallyadjusted. The automatic adjustment may be performed by using broadcastedreference signals, such as the Public Broadcasting Station (PBS) timesignal, or using Global Positioning System (GPS) signals or the like.The manual approach may be performed by the user specifying the new timezone or by the system detecting that the user has set the system clockto a new time. The calendar/scheduling system then updates scheduledevents by looping through each event record or entry and normalizing thetime entry to Greenwich Mean Time (GMT). The normalized time entries arethen converted to the new “local” time.

While the Fu et al. system reduces the complexities of time zoneadjustments, user intervention is still required, if the device is notenabled to determine the present time zone by using PBS or GPS signalsthat are wirelessly received. What is needed is a device and method forproviding automated time zone tracking of the present location of thedevice, without requiring reception of location-specific signals.

SUMMARY OF THE INVENTION

A portable processing device includes a time-of-day clock that isadjusted dynamically in accordance with a travel schedule that is storedin memory. The travel schedule is a stored itinerary that includesdeparture and arrival information. When it is determined that theitinerary identifies travel that includes at least two time zones, thetime-of-day clock is updated to have a correlation with the departureand arrival information. Thus, after identifying occasions on whichanticipated travel includes travel among time zones, the clock isautomatically changed in response to detecting coincidences with thetiming of such occasions.

The dynamic time-of-day adjustments include the step of receiving theitinerary. In one embodiment, the user enters the departure and arrivalinformation by means of a user interface mechanism. For example, if theportable processing device is a laptop computer, the user interfacemechanism may be a keyboard. In another embodiment, the itinerary isdownloaded from another processing device, such as a desktop computer.Thus, the portable processing device can be “hotsynced” with astationary processing device having a compatible calendar program. As athird alternative, the travel schedule may be received in an electronicitinerary messaging format, so that if a customer has made airline orhotel reservations electronically, the information can be downloadeddirectly to a calendar program of the portable processing device,without requiring the user to manually enter the information.

The invention also includes a step of determining the relevant timezones. In one application, there is a database stored within theportable processing device. The database may include geography-based andtime zone-based information. For example, a database application thatincludes a list of cities and the time differentials relative toGreenwich Mean Time may be employed. A more extensive database may beused, if the database is available via a network. When such a databaseis not locally or remotely accessible, the portable processing devicemay include a software module which prompts the user to enter the timezone information as travel information is entered.

As another step, the dynamic adjustments of the time-of-day clock arecorrelated with the departure and arrival information of the itinerary.Preferably, the clock adjustments occur en route of the travelanticipated by the itinerary. For example, the adjustments may betriggered by recognizing that a departure time or an arrival time hasbeen reached. The adjustments may be in one hour increments, but otherincrements are contemplated. For example, if departure and arrivalinformation indicate that there is an eight hour time difference thatwill be encountered over a ten hour time period, time zone incrementtokens of 1.25 hours (10/8) may be stored in a calendar program. Eachtoken indicates that at that moment, there is a crossing from one timezone to a next time zone. Although this method is not precise, it issufficiently close for purposes of the dynamic clock adjustment. Similartokens may be automatically stored for the return trip, although thetokens will be time zone decrements rather than increments.

Another feature of the invention is the display capability. In thepreferred embodiment, there are at least two displayed times. A firsttime is referred to as the reference time. The reference time is thetime at a particular geographical location, such as the home city of theuser. In the embodiments in which reference time is tracked, thereference time is not dynamically adjusted for travel. Instead, a seconddisplayed time is dynamically adjusted in correlation with arrival anddeparture information of the itinerary. All reminders, alarms and ToLfunctionality are based on the second (local) time, rather than thereference time.

The portable processing device may be a laptop computer, PDA or otherdevice in which maintaining time synchronization is important. Theinvention is particularly suitable for applications in which a userrelies on a portable processing device for calendaring, messaging andToL functionality. Optionally, the device may be programmed to confirmthe adjusted time by accessing an external source of information. If thedevice has a wireless connection to a network, the network can be polledto determine the local time, when protocol permits. Alternatively,devices that are equipped with GPS locators can use GPS signals toconfirm the adjusted time. In like manner, a GSM system could be used toconfirm the time zone based on determining the location of theantenna/base station that is accessed by the portable processing device,such as when the device is a cellular phone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a portable processing device in accordancewith the invention.

FIG. 2 is a process flow of steps for dynamically adjusting atime-of-day clock in the device of FIG. 1.

FIG. 3 is a process flow of steps for acquiring and processinginformation important to the implementation of the process of FIG. 2.

DETAILED DESCRIPTION

With reference to FIG. 1, components of one embodiment of a portableprocessing device having a dynamically adjustable time-of-day clock 10are shown. The device may be a laptop computer, a PDA, a watch, acellular phone, or any other portable device that is relied upon fordetermining time. For example, the device may be a telephony-enabledlaptop computer that is addressable by a ToL system in forwarding callsor allowing calls to ring through, based upon the time of day. Thus, ifa traveler with a laptop computer is in a time zone different than thetime zone of a home office, the selection to alert the traveler that anincoming call is available should be based upon the time at the physicallocation of the traveler, rather than the physical location of the homeoffice. The desired operation of the computer when it is connected to ahotel LAN port or a phone port or when it is wirelessly accessibledepends upon the accuracy of the time-of-day clock 10.

In the preferred embodiment, the portable processing device includesmemory 12 having an internal database 14 and an itinerary program 16.The itinerary program may be a conventional electronic calendar that isaccessible by a personal information manager program executed by aprocessor 18. As will be explained more fully below, the storeditinerary 16 includes a travel schedule of departure and arrivalinformation. The arrival and departure information may be the dates andtimes of airline flights, hotel reservations, vehicle rentalreservations, and similar travel-related events.

The information in the database 14 may be a list of cities and the timezones associated with each city. Greenwich Mean Time (GMT) may be usedas a standard, so that each city is identified as having a timedifference relative to GMT. Thus, a time-of-day clock adjustment may bedetermined by converting the known time at the home office to GMT andthen comparing the GMT to the time in the city in which the user isphysically located. The device of FIG. 1 includes a time calculator 20for performing such determinations.

The device also includes a user interface mechanism 22. The mechanismmay be a keyboard, computer mouse, trackball, or similar device forallowing a user to enter information to the device. Thus, a user caninput information to the itinerary program 16 or the database 14 or canrespond to prompts that are presented to the user when itineraryinformation is input.

An input/output (I/O) mechanism 24 may be connected to anotherprocessing device, such as a computer, or to a network. The I/Omechanism is a conventional component that may include a first port 26for connection to a computer and a second port 28 for connection to anetwork. If the device does not include the internal database 14, anexternal database may be accessed by the device using either the firstport 26 or the second port 28. Moreover, the ports may be used to inputthe travel schedule stored at the itinerary 16. In one application ofthis feature, the user of the device enters the information into theitinerary 16 of the portable device by linking the device to a laptop ordesktop computer having the information. The two computers can then be“hotsynced,” if the computers utilize compatible software, such as aPersonal Information Manager (PIM) program with an electronic calendar.In another application of this feature, the second port 28 is used toconnect the device to a network from which electronic itinerarymessaging can be received. For example, if a customer receives anelectronic confirmation via the global communications network referredto as the Internet, the confirmation may be the source of the travelinformation to the itinerary. This download would reduce the need of theuser entering the information via the user interface mechanism 22. Inanother application of this feature, the portable device is networkattached (e.g., a connection to a LAN), so that travel information canbe received from a central facility.

In the preferred embodiment, the portable processing device isconfigured such that a display is able to show two times. The firstdisplayed time identifies the time-of-day in the geographical locationin which the user is determined to be physically located, based upon theinformation in the itinerary 16. This current location-based time isrepresented by component 32. The second displayed time is a referencetime, as represented by component 34. As an example, the reference timemay be displayed in parentheses next to or below the currentlocation-based time. This allows the user to easily determinetime-of-day at the location at a home office, if a call to the office isnecessary. However, any reminders, alarms, or ToL functionality of theportable processing device will operate according to the currentlocation-based time. Thus, no early morning phone calls will trigger anaudible alert that an incoming call is available.

The process steps for executing the dynamic clock adjustment of thedevice of FIG. 1 will be described with reference to FIG. 2. In step 36,the time-of-day clock 10 is set. Typically, a user will set the clockbased upon the time at the location in which the user first acquires thedevice. However, this is not critical. The execution of step 36 is notsignificant to the invention. Nevertheless, in the preferred embodiment,the device maintains a reference time and a dynamically adjusted time.The reference time is typically established in step 36, while theadjusted time is based upon step 36 and upon travel of the device.

In step 38, the itinerary is input into the device. The itineraryincludes departure and arrival information. The device is unable todetermine whether actual travel occurs. Thus, the dynamic adjustmentthat is calculated by the time calculator 20 is based upon “anticipatedtravel,” rather than actual travel. In some embodiments, the dynamicadjustment of the time-of-day clock 10 will lead to a display ofinaccurate time information, if a user postpones a trip without updatingthe information in the itinerary 16 of the memory 12. However, in otherapplications the device is enabled to confirm the adjusted time. Forexample, devices that are equipped with GPS locators can use GPS signalsto confirm the adjusted time. Similarly, a GSM system can be used tocalculate the time zone based on the location of an antenna/base stationthat is accessed by the portable processing device, such as when thedevice is a cellular telephone.

In step 40, a coincidence between the clock and the timing of ananticipated trip is identified. That is, when the time-of-day clock 10reaches a date on which a trip is scheduled, as indicated by theinformation in the itinerary 16, the dynamic adjustment process isinitiated. Preferably, the clock adjustment occurs simultaneously withthe trip, so that the adjustment occurs en route. For example, at thetime that an airline flight is scheduled to depart, as indicated in theitinerary 16, the step 42 of determining whether the trip involvestravel in more than one time zone is implemented. If the trip involvesonly one time zone, no clock adjustment is necessary. Consequently, theprocess returns to the step 40 of identifying a coincidence between ascheduled trip and the time-of-day clock. On the other hand, if the tripinvolves more than one time zone, a step 44 of adjusting the clock isimplemented.

The execution of the clock adjustment at step 44 is preferablyincremental. That is, while the clock may be adjusted in a leap forwardor backward to the appropriate time at the destination, the preferredembodiment is one in which tokens are added or subtracted while the tripis in progress. This preferred embodiment is particularly useful whenthe portable processing device is used during travel, such as when alaptop computer is used during a flight. The adjustment may be in onehour increments, but other increments are contemplated. As an example, auser may have used Pacific Standard Time in setting the clock in step 36and may have a ten hour flight from San Francisco to London, with theflight leaving San Francisco at 2:00 PM local time and arriving inLondon at 8:00 AM London time. Since the eight hour time difference isencountered over a ten hour period, a time zone increment token may bestored every 1.25 hours (10/8). Each stored token indicates a crossingfrom one time zone to a next time zone. While the process is notprecise, it is sufficiently close in most uses. Upon arrival, thereminders, alarms and ToL functionality will function according toLondon time. The display of time will indicate the London time, but thereference time is preferably also displayed, as indicated at step 46.When returning from London, time zone decrement tokens are generated,similar to the time zone increment tokens during the original airlineflight.

FIG. 3 illustrates optional and alternative steps for executing the FIG.2 steps 38, 40 and 42 of inputting the itinerary and identifyingcoincidences between the occurrence of a trip and the present time. Instep 48, a user inputs travel information via the user interfacemechanism 22 of FIG. 1. This may include generating prompts,particularly if the portable processing device does not include the timezone-based database 14. Thus, the prompts may require a person toidentify any time zone differences. Prompts may also be used to ensureaccuracy in the input of information. When a user inputs appointmentsscheduled for a time in which a user will be in a city having adifferent time zone, the device may generate a prompt requesting aselection between the present time zone and the destination time zone.Other types of prompts may also be generated, as will be described withreference to step 56.

As an additional or alternative step to inputting the itinerary in step48, the travel information may be downloaded from a compatible programof a second processing device. For example, the port 26 of FIG. 1 may beconnected to a desktop computer in which a calendar program has beenupdated to include all of a known travel schedule. The download step 50is sometimes referred to as a hotsync. As indicated at step 52, thetravel information can additionally or alternatively be downloaded via anetwork. The network may be a private network, such as a LAN, or may bethe global communications network referred to as the Internet. Airline,hotel and car rental reservations are sometimes confirmed electronicallyby means of transmissions over the Internet. These electronicconfirmations may be downloaded and used to update the itinerary 16 inthe memory 12.

Step 54 involves accessing a time zone-based database. In the preferredembodiment, the database is internal to the device, as indicated by thedatabase 14 in memory 12 of FIG. 1. However, the database may also becentrally located if the device is network compatible. The access to adatabase allows the device to determine when travel informationindicates that there will be a trip from one time zone to a second timezone. As described above, the database may be a list of cities and thetime zones appropriate for those cities. As an alternative to using thedatabase to identify multi-zone travel, a user may be prompted at step56 to input identifications of relevant time zones when the travelinformation is entered. Requiring a user to identify the time zones ismore time consuming and is more prone to error than the previouslydescribed techniques, but manual entry may be helpful, since thedatabase cannot be exhaustive.

In step 58, the occasions on which anticipated travel includesmulti-zone travel are identified. This is a continuation of the step ofaccessing the time zone-based database 54 and generating the timezone-based prompts 56. The occasions of multi-zone travel can be taggedin memory in order to facilitate the step 60 of tracking the occurrencesof the occasions.

An advantage of the invention is that the device and method do notrequire a user to regularly update a time-of-day clock. Instead, theappointments that are entered into an electronic calendar areautomatically used to dynamically adjust the clock when appropriate.

What is claimed is:
 1. A portable processing device comprising: atime-of-day clock; memory having stored information indicative ofcalendar activities that include at least one of reminders and alarms,said memory further including a travel schedule that includes departureand arrival information; and processing means in communication with saidmemory for automatically updating said calendar activities and saidtime-of-day clock based upon determinations that said travel scheduleidentifies travel that includes at least two time zones, said processingmeans being configured to initiate said updating as direct automatedresponses to accessing said departure and arrival information stored insaid memory.
 2. The portable processing device of claim 1 wherein saidmemory stores said departure and arrival information to includezone-based data that enables said processing means to determinetime-of-day clock and calendar activities updates based uponcorrelations between said zone-based data and said departure and arrivalinformation.
 3. The portable processing device of claim 2 wherein saidmemory stores said travel schedule as an itinerary and stores saidzone-based data as a database of geographical locations and time zonesfor said geographical locations, said processing means being configuredto correlate said itinerary with said database and to coordinate updatesof said time-of-day clock with correlations between said itinerary andtime zone changes relevant to said itinerary.
 4. The portable processingdevice of claim 1 further comprising a display means responsive to saidprocessing means for visually displaying an updated time and a referencetime, said updated time being indicative of said updating of saidtime-of-day clock, said reference time being indicative of a time withina selected time zone and being isolated from said updating based uponsaid travel.
 5. The portable processing device of claim 1 furthercomprising an input means for receiving said travel schedule from anetwork connection.
 6. The portable processing device of claim 5 whereinsaid input means includes a connection to a commercial website of theWorld Wide Web.
 7. The portable processing device of claim 5 whereinsaid input means is an input/output port compatible with connection to acomputer having a calendar program.
 8. The portable processing device ofclaim 1 wherein said processing means is configured to incrementallyupdate said time-of-day clock based upon said time zone changes, saidincremented updates being triggered to coincide with travel representedin said travel schedule.
 9. The portable processing device of claim 1further comprising means for prompting user inputs of information assaid travel schedule is input to said memory.
 10. A method ofautomatically updating a clock and a calendar program containingcalendar activities that include time-specific appointments of aportable device comprising steps of: storing travel information specificto anticipated travel of said portable device; identifying occasions onwhich said anticipated travel includes travel among time zones; andautomatically changing said clock and said calendar activities inresponse to detecting that a time indicated by said clock has at leastreached timing of one of said occasions, including varying said clockand said calendar activities based upon occurrences of said anticipatedtravel.
 11. The method of claim 10 wherein said step of automaticallychanging includes incrementing and decrementing said clock and saidcalendar activities in correlation with in-route movement of saidportable device, including basing timing of said in-route movement uponsaid anticipated travel across time zones.
 12. The method of claim 11wherein each occurrence of said steps of incrementing and decrementingis implemented provides a time change not exceeding one hour, said timechange compensating for said anticipated travel from a first time zoneto a second time zone.
 13. The method of claim 10 wherein said step ofautomatically changing is based solely upon time-based processing withinsaid portable device.
 14. The method of claim 10 wherein said step ofstoring said travel information includes downloading said travelinformation from a global communications network.
 15. The method ofclaim 10 further comprising a step of selectively displaying a referencetime and an updated time, said reference time being indicative of thetime-of-day in a selected time zone and said updated time beingresponsive to said automatic changing of said clock.
 16. The method ofclaim 15 further comprising a step of requesting selections among timezones when said travel information is input to said portable device,said selections being related to times at different geographicallocations specified in said travel information.
 17. A method ofautomatically updating a clock and a calendar program having calendaractivities of a portable device comprising steps of: maintaining aninternal time-of-day clock; maintaining a calendar program to includetime sensitive reminders and alarms and information indicative ofgeographical locations in which said portable device is anticipated tobe as of specific dates; automatically adjusting said time-of-day clockbased upon said information of said calendar program, including changingsaid time-of-day clock in response to detecting that a specific date hasbeen reached on which a change in said geographical location of saidportable device results in a change in time zones; and displaying bothsaid automatically adjusted time-of-day clock and an unadjustedreference time-of-day clock that is indicative of time that is trackedin isolation of said step of automatically adjusting.
 18. The method ofclaim 17 further comprising a step of maintaining a database in whichgeographical locations are correlated with time-of-day information, saidstep of automatically adjusting including accessing said calendarprogram and said database to determine specific dates in which saidchanges in said geographical locations result in changes in time zones.